Not a bad idea.
If the pole piece is undercut a tad so this coil is under the center of the voice coil, it can be used to exclude flux thereby linearizing inductance.
Any gap flux modulation would have to go through the entire magnetic circuit though, so that would require making the entire mag circuit out of stamped laminations roughly .5 mm thick or less, oriented correctly for eddy elimination.
For that structure, the comp drive coil could be back down the pole piece away from the vc.
jn
If the pole piece is undercut a tad so this coil is under the center of the voice coil, it can be used to exclude flux thereby linearizing inductance.
Any gap flux modulation would have to go through the entire magnetic circuit though, so that would require making the entire mag circuit out of stamped laminations roughly .5 mm thick or less, oriented correctly for eddy elimination.
For that structure, the comp drive coil could be back down the pole piece away from the vc.
jn
Doing the out the box thinking. IF the idea is to keep the VC in the linear part of the field as much as possible and you've made the VC as short as possible and the gap as long as possible and the speaker as efficient as possible then you get to a point where moving the magnet might start to be less trouble than some of the things being discussed. It's extreme LF where these issues are worst after all...
If you wanted to reduce interactions, what about the sensing coil on the inside, with a shield? As long as you don't block the airflow you have room to do motion sensing there.
But if I get Keantoken right, sensing loops at the right points could be used like limiters as well for excursion.
BTW Thrax audio claims to use motional feedback control on their sub... if anyone wants to try an see if they have a patent.
But if I get Keantoken right, sensing loops at the right points could be used like limiters as well for excursion.
BTW Thrax audio claims to use motional feedback control on their sub... if anyone wants to try an see if they have a patent.
The impedance sweeps show no reciprocity (posts 189 to 201)
Cartridge dynamic behaviour
I am fiddling with some measurements trying to check reciprocity at the magnetic circuit of an old Stanton MM.
Preliminary data are surprising and I can’t explain the 30 to 40dB that I see. I will rerun the tests and report there.
George
High-Fi? | Stereophile.com
Really not sure how to read the comment made by the stereophile whistler about JC, but some nice soundbytes from NP. The crux of the essay is though sadly pish.
Really not sure how to read the comment made by the stereophile whistler about JC, but some nice soundbytes from NP. The crux of the essay is though sadly pish.
I know Nelson knows some of the characters, he is being very kind in some cases since the exact opposite is true for quite a few notable ones. Unless of course a posse comitatus is your idea of counter culture. Unfortunately I can only share stories in private.
OK. I'll tell about one I met.
David Hafler.
After E.Borbley left, i was called to see if I want to replace him. I had consulted on the XL-280 design from long distance. Hafler paid for me to fly out from Calif to NJersey and spend a few days talking to the people and being interviewed. On the last day, David came to meeting at the factory with all tech people there and asked me some philosophical design questions. He was very opinionated about designs. He didn't see why my CFA design was any better than his companies.... preamp. He pressed me on that... asking for proof or some explanation. It annoyed me and I was afraid I would not have freedom to be creative there. Very controlling man. I answered him in a nasty tone and he then left. Said to others he didnt want me but it was thier decision. They wanted me. I had fun with them... dinner at house etc.
i dont think he was used to being told off. Nicely though, I thought, but my tone of voice was aggressive. I learned he was very very wealthy man who owned several radio and TV stations and did not need Hafler Audio business... it was a hobby business which was profitable at the time. I turned the job offer from the crew down. Because of Hafler's attitude towards designing.
Later that year I went to CES and said I was exhibitor David Hafler and they gave me a badge to get in.
If you are well known name and wealthy, they dont dare ask you for your drivers license/ID. I went to his suit/demo room and said hello and pointed to his name on my badge. He didnt blink an eye about it. Didn't care.
That was last time I saw him.
RIP David.
-Richard
David Hafler.
After E.Borbley left, i was called to see if I want to replace him. I had consulted on the XL-280 design from long distance. Hafler paid for me to fly out from Calif to NJersey and spend a few days talking to the people and being interviewed. On the last day, David came to meeting at the factory with all tech people there and asked me some philosophical design questions. He was very opinionated about designs. He didn't see why my CFA design was any better than his companies.... preamp. He pressed me on that... asking for proof or some explanation. It annoyed me and I was afraid I would not have freedom to be creative there. Very controlling man. I answered him in a nasty tone and he then left. Said to others he didnt want me but it was thier decision. They wanted me. I had fun with them... dinner at house etc.
i dont think he was used to being told off. Nicely though, I thought, but my tone of voice was aggressive. I learned he was very very wealthy man who owned several radio and TV stations and did not need Hafler Audio business... it was a hobby business which was profitable at the time. I turned the job offer from the crew down. Because of Hafler's attitude towards designing.
Later that year I went to CES and said I was exhibitor David Hafler and they gave me a badge to get in.
If you are well known name and wealthy, they dont dare ask you for your drivers license/ID. I went to his suit/demo room and said hello and pointed to his name on my badge. He didnt blink an eye about it. Didn't care. That was last time I saw him.
RIP David.
-Richard
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Later that year I went to CES and said I was exhibitor David Hafler and they gave me a badge to get in.
You should have told them you were Prince.
and have women falling all over themselves and throwing their panties at me??
-RM
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